| 摘要 |
PURPOSE:To automate the test of a laser control circuit by adopting the constitution that a DA converter set so that a photodiode detection voltage at write power lighting represents a read power level controls the subtraction of the write power level current. CONSTITUTION:A photodiode (PD) current/voltage conversion section 12 is provided, which obtains a prescribed lighting power even when a laser diode (LD) having a specific characteristic is used. The light power of the LD unit 1 is controlled by using analog switches 13, 15 to turn on/off automatic control means 3, 5 and automatic power control means 8, 17. Then the control is executed by a DA conversion means at the read power level and by the setting value of DA conversion means 7, 14 at the write power level. Thus, the test of the laser control circuit is automated and even when the LD unit is replaced, the specified light power is attained for the control. |
